Normally an electronic device has an antenna for wireless communication. Recently such an antenna is embedded in the electronic device so as to realize an elegant and size-reduced electronic device.
Meanwhile, a housing of the electronic device is often manufactured with metal. While this metal housing has advantages of improving an outward appearance and enhancing a stiffness, it causes degradation in performance of an embedded antenna. In order to obviate this problem, such a metal housing itself is also used as an antenna.
Typically, a metal housing is manufactured through a casting, a computerized numerical control (CNC), an extruded molding, a rolling, a forging, etc., and also improves antenna performance through an injection so as to prevent degradation of antenna performance due to metal residing on a rear face thereof. However, in this case, a boundary produced between a metal part and an injection part on the metal housing is not smart and appears as a segmented form. Therefore, in order to secure the uniformity in the metal part and the injection part, a process of coating the entire rear face may be applied or the injection part may be exposed.
In case of coating the metal housing to secure the uniformity in the metal part and the injection part, several colors may be used for the metal housing through partial coating or printing with partial masking. However, such a coating on the metal housing may remove the intrinsic texture of metal and also make it difficult to differentiate the metal part from the injection part. Alternatively, in case of fitting any additional member formed of glass, metal, etc. so as to conceal a boundary between the metal part and the injection part, the thickness of the housing may be increased and an undesirable bonding issue may be caused.